package section_11;

import net.mindview.util.Countries;

import java.util.*;

import static net.mindview.util.Print.print;

/**
 * @Author ZhangGJ
 * @Date 2019/10/02
 */
public class ReadOnly {
    static Collection<String> data = new ArrayList<String>(Countries.names(6));

    public static void main(String[] args) {
        Collection<String> c = Collections.unmodifiableCollection(new ArrayList<String>(data));
        print(c); // Reading is OK
        //! c.add("one"); // Can’t change it
        List<String> a = Collections.unmodifiableList(new ArrayList<String>(data));
        ListIterator<String> lit = a.listIterator();
        print(lit.next()); // Reading is OK
        //! lit.add("one"); // Can’t change it
        Set<String> s = Collections.unmodifiableSet(new HashSet<String>(data));
        print(s); // Reading is OK
        //! s.add("one"); // Can’t change it
        // For a SortedSet:
        Set<String> ss = Collections.unmodifiableSortedSet(new TreeSet<String>(data));
        Map<String, String> m =
            Collections.unmodifiableMap(new HashMap<String, String>(Countries.capitals(6)));
        print(m); // Reading is OK
        //! m.put("Ralph", "Howdy!");
        // For a SortedMap:
        Map<String, String> sm =
            Collections.unmodifiableSortedMap(new TreeMap<String, String>(Countries.capitals(6)));
    }
}
